Z-Axis Dropping

[shodwilliams]

I have been using the CNC Shark Extended bed for about 2 months, and just recently, the Z axis started to fall when the controller was powered down. Is this normal?

[sharkcutup]

I have had my Shark Extended Bed since March of this year and it does the same thing too! I use a clamp to hold it up as a precaution when I power down. Sometimes it will stay up on its own but I still put the clamp on it as a precautionary measure.

[shodwilliams]

Well, I am glad I am not the only one.

[Rando]

Yup, mine does too, though in my case it's from the heavier water-cooled spindle. If I need to keep Z overnight, I "park" the head on a block that consists of (bottom to top) 3" block of "florist foam" with 1/2" anti-fatigue-mat foam rubber on top. I go ahead and jog the head down so it depresses just enough into the block (the florist foam crushes at just the right force) so that the weight is supported. If I need to also leave an endmill in the chuck, I use a 1x3" piece of ~80mil plastic sheet on top so the bit doesn't pierce the foam. That has worked well for me, 'cause yeah, losing Z is a daily pain for a multi-part run where I need to turn it off overnight. You can see the block on the left in the photo (of my aluminum-chip cluttered machine). Florist foam is the stuff they put in the bottom of vases to make the flowers stay in place; very cheap at a craft store.